Precision balance



J. GATTONI PRECISION BALANCE Original Filed Feb. 8, 1938 Sept. 29,1.942.

4weights which .are

`means for lifting these weights @if Patented Sept. 29, 1942 JohnGattoni, Union Cit erer-Kohlbusch, Inc. poration of New Jer y, N. J.,assigner to Seed- Jersey City, N. J., a corseyOriginalapplication.February 8, 1938, Serial No.

189,314. VDivided. and this application March 1.1, 19,49, Serial No.323,412

Claims. (Cl. 265-54) This invention relates to balances and is adivision of my copending application Serial No. 189,314,.led February 8,.-1938, now Patent No. 2,192,905, issued March .12, 1940.

The object of the invention is to provide an V'improved precisionbalance v'for vquickly and accurately weighing objects of relativelysmall-mass.

Another object fof the invention .is to provide a balance of theabovetype ,in which weighing can be accomplished easily, quickly andaccurately, and in which a wider variety of weight combinations can beobtained with fewer parts and adjustments ,than'heretofore 'Theinvention fis particularly applicable Ato sensitive rbalances .ofalysts, chemists,'jewelers, etc. 'wellknowlL balances of this typeinclude sa zbeam which is delicately balanced on a knife edge andcarries a pan or a pluralityof pans for supporting the .substance to beweighed as well as a set ,of known .used in the weighing loperation.These balances customarily employ movable poises on the beam, oradjustable chains, etc., suspended from ,the beam for weighing purposes.

My invention resides in the provision of a weight support rwhich may be.suspended from a balance beam .and which is adapted to support aplurality of weights 'which are stacked thereon in superimposedrelation, and inthe provision of or placing them on the support in anydesired number in accordance with the `nature of the substance to beweighed. In this manner any desired vnumber of known weights may bepivotally suspended from a common point on the beam, `andall saidweights may-be controlled bythe manipulation of a single shaft or othercontrol means operated from outside the balance case.

Another feature of the invention resides in the provision of means forcoordinating the operation of the Weightlifting mechanism with theoperation of the bridge or cradle `which serves to lift the pivoted beamand'pan supports oli their respective knife edge bearings when theweights and materials are being deposited .on or removed from thebalance. `By so coordinating the operation of these mechanisms I `makeit possible to move the weights on and off the weight support only whenthe beam and pan supports are oiT their bearings and -in a position cfrest, .which prevents jarring of the-delicate mechanisms and furthermoreexpedites the weighing operation.

These and other features and advantages of the inventionwill bedescribed in-detail in conthe type employed by -an- `edge bearingnection with the accompanying drawing, which:

Fig. 1 is a front elevation of ing my invention;

Fig. 2 is a vertical sectional viewof the weightlifting mechanism, takenon line 2-2 of Fig. 3;

Fig. 3 Ais a plan view showing the gears controlling the operation ofthe dial land weightselecting mechanism;

Fig. 4 is a plan View adjustable lifting means;

Fig. 5 is a vertical sectional view taken on line 5-5 of Fig. vl; and

Fig. 6 is a detail Fig, l.

The balance shown in the-drawing has a base vl supporting case 2 whichencloses thedevice and is provided with transparent windows 3 and asliding front of the type commonly employed in balances of this type.

The base supports a standarddhaving a knife 5 carrying the centralknife-edge 6 of beam 'l as shown in Fig. 1.

The balance shown herein for purposes of illustration is calibrated interms of grams, and the beam 1 is provided with two coeXtensive sets ofcalibrations and notches 8 and 9 respectively, being similar in thisrespect to the vbeam disclosed Vin J. E. Seederer Patent #1,972,603 ofSeptember 4, 1934.. Thesmaller series of notches 8 comprises ten notchescalibrated from zero to milligrams by ten milligram increments, whilethe larger series 'of notches 9 comprises ten notches calibrated fromzero to 1,000 milligrams by one `hundred milligram increments.

A rotatable and horizontally movable shaft is suitably mounted in thecase -2 ladjacent the top of the beam 1, passing through a bearing vl2inthe case and Vbeing provided with a knob or finger piece i3 outsidethe case for ycontrolling the movement of the shaft. Within the case,shaft l0 carries an arm i4 having a pair of opposed grips of standardconstruction which are adapted to receive the poisescommonly employed inbalances of this type for the purpose of lifting the poises and carryingthem from one of the notches 8 or 9 to another such notch when the shaftI0 is actuated from outside the case.

The beam 'l hasdepending arms vI6 at its outer ends carrying suitableknife edges Il on which rest the knife edge bearings of yoke frames i8.These yoke frames carry pivoted hooks I9 which support the bows 28 ofconventional weighing pans 2| as shown in Fig. 1. The standard 4 alsosupports the usual bridg'e'or cradle 23 which is a balanceembodyof theweights and the section taken on line-G o1' raised and lowered byvertical plunger 24 within the standard 4 for the purpose of liftingbeam 1 and yoke frames IS off their respective knife edge bearings whenthe weights and materials are being placed in and removed from pans 2lor when the balance is not in use. Plunger 24 is actuated by a cam 25carried by rotatable shaft 26 which extends through the bottom of thecase and is rotated by a suitable knob which is conveniently located atthe front of the balance.

The balance shown here for purposes of illustration is also providedwith a magnetic damper consisting of a suitable aluminum or othernonmagnetic damping plate which is suspended from the yoke frame I8 atthe left-hand end of the beam as viewed in Fig. 1 and is adapted to moveup and down between the closely spaced poles 21 of a permanent magnet 28which is carried by a bracket 29 mounted on standard 4 as set forth inmy Patent #1,900,641 of March 7, 1933. In this manner swinging movementof the pan bows 29 and associated parts are isolated from the dampingplate and the damping plate is prevented` from striking against thepoles of the magnet which would seriously aifect the sensitivity andaccuracy of the balance. The eddy currents set up by moving the dampingplate through the magnetic field dampen the motion of the beam and bringthe balance to rest in a few seconds. The beam 1 carries the usualpointer 39 which moves over a scale 3i at the front of the balance asshown in Fig. l.

The hook I9 at the right-hand end of the beam 1, as viewed in Fig. l,has a depending extension 33 carrying a flat-faced weight support 34having a centrally disposed lug 35 of rectangular cross-section whichserves to center a plurality of superimposed weights 33 on the support34 as shown in Figs. 2 and 4. In the embodiment illustrated, the weights33 are nine in number, each weighing one gram. These weights are all ofthe same general flat diamond shape and they all contain central cut-outportions or holes 38 of rectangular shape adapted to fit over therectangular lug 35 so as to permit the weights to rest one above theother upon the support 34. As illustrated in Figs. 2 and 4, however, therectangular holes 33 are staggered in the respective weights 33 in sucha way that the weights are caused to spread out fan-like with thediamet- Y rically opposite outer ends of 'each weight projecting freeand clear of their neighbors when the weights are superimposed in nestedposition on the support 34 as in Fig. 4 of the drawing.

When all the weights 35 are thus stacked on the 't support 34 it will beevident that their combined weight of nine grams will be suspended froma single point on beam 1. However, by means of the weight liftingmechanism illustrated in Figs. 1 to 6 it is possible to lift any desirednumber of the weights 36 off the support 34 and therefore off thebalance beam.

The mechanism for lifting and supporting the weights 35 clear of theweight support 34 includes a vertically movable rod 43 mounted inside arotatable sleeve 4l within a column 4?. supported on the base of thebalance as shown in Figs. 1 and 5. The vertically movable rod 49supports a platform 43 on which a cylindrical housing 44 is rotatablymounted by means of a shaft 45 which is journaled in the platform 43 asshown in Fig. 2. The shaft 45 of housing 44 carries a gear 41 meshingwith an idler gear 48 which, in turn, meshes with a gear 49 which isrotatably mounted on the vertically movable rod 40 as shown in Figs. 2and 5. Gear 49 carries a depending pin 50 which telescopes within asmall cylindrical sheath 5l carried by the head 52 of the rotatablesleeve 4l as shown in Figs. 1 and 5. Hence when sleeve 4l is rotated, bymeans hereinafter described, the head 52 and sheath 5I are likewiserotated, causing rotation of pin 59 and gear 49 which therefore causerotation of idler gear 48, gear 41, shaft 45 and housing 44. However, itwill be noted that the vertical plunger-like movement of the dependingpin 5! of gear 49 in sheath 5l permits the platform 43 carrying thetrain of gears and the housing 44 to move up and down with the rod 40when said rod is actuated by the means hereinafter described. Thevertically movable platform 43 also carries a depending guide pin 54which acts in a bifurcated extension 55 mounted on the column 42 asshown in Fig. 5.

The cylindrical housing 44 is positioned in alignment with the support34 Vcarrying the weights 33 and is of a diameter sufficient to receivethese weights when they are in the fan-like nested position shown inFig. 4. The weights are thus permanently carried within the housing 44and the housing is preferably enclosed by a cover 55 having a radialslot 51 which permits the cover to be slipped over the extension 33carrying weight support 34, after which slot 51 may be closed by meansof a metal strip 58 which is adapted to be clamped over the edge of thecover 55 as shown in Fig. 2. Within the housing 44 there are mounted twodiametrically opposite flat-faced segments or ledges 59 of suitable sizeand shape, which are adapted to engage and lift the weights 35 olf theirsupport 34 in any desired combination for the purpose of adding weightsto or subtracting weights from the support 34. For this purpose thesegments 59 are so positioned on the peripheral wall of housing 44 thatthey will lie beneath the horizontal plane of the weights 35 when thehousing 44 has been lowered by the descent of the actuating rod 43 inthe column 42.

When the rod 49 and housing 44 are in their l lowered position, withsegments 59 lying beneath the plane of the weights 33, the weights 33will all rest on their common support 34 in the fanlike positionillustrated in Fig. 4, and it will be evident that the housing 44 may befreely rotated by rotation of sleeve 4l in column 42 to bring theweight-lifting segments 59 into a position where they will either clearall of the weights 36 or else will engage any weight or combination ofweights 35 when the housing 44 is subsequently raised by the elevationof rod 49 in column 42. In Fig. 4, for example, the housing 44 has beenrotated to a position such that the segments 59 are directly beneath thefourth and ith weights 35, counting from the bottom of the stack ofWeights, and it will therefore be evident that when housing 44 issubsequently raised by raising rod 43 the segments 59 will lift thefourth and fifth weights 33 as well as the sixth, seventh, eighth andninth weights which are superimposed thereon, and that only the threeweights at the bottom of the pile will remain suspended on the support34 as shown in Fig. 2. When this condition prevails the total weightsuspended on the support 34 is that represented by the three lowermostweights, or in this case three grams since these weights are each onegram as stated above. In order to yindicate the weights carried by theweight support 34 the housing 44 carries a dial 59 cooperating with apointer 5I which is marked on the platform 43 as shown in Fig. l. Thedial 60 is graduated in grams from 0 to 9 by one gram increments, thecalibrations corresponding to the number of possible combinations inwhich the weights 36 may be suspended on the support 34 as describedabove.

The vertical movement of rod 46 carrying platform 43 and housing 44 iscontrolled by a lever 63 which is pivoted to the underside of the base lat 64. At one end lever 63 is pivotally connected by a link 65 to thecame 25 carried by the rotatable shaft 26 which controls the verticalmovement of plunger 24 for raising and lowering the cradle 23 of thebalance as previously7 described; while the opposite end of lever 63 isshaped as indicated at 66 to engage and support the lower end of rod 40.Accordingly, rotation of control shaft 25 in a clockwise direction asviewed in Fig. 1 causes lever 63 to cant in a clockwise direction,thereby lowering rod 40 in column 42 and therefore also loweringplatform 43 and housing 44 so that all of the weights 36 will besuspended on support 34 and segments 59 will lie beneath the plane ofthe weights 36; and at the same time cam 25 of control shaft 26 willraise plunger 24 in the main column 4 of the balance and thereby raisethe cradle 23 which lifts the beam l and yoke frames I8 off theirrespective knife edge bearings. When the parts are in this position,rotation of sleeve 4| may be accomplished by means of a knob orngerpiece 6l carried by shaft 68 which is journaled in the side of thebalance case 2 and in a bracket 69 which depends from the base I asshown in Figs. 1 and 5. Shaft 68 carries a worm 1.0 which meshes with aworm wheel Il keyed to the sleeve 4| as shown in Fig. 5. As illustratedin Figs. l, 5 and 6, shaft 68 carries a toothed wheel 'I2 which isadapted to be engaged by the edge of lever 63 when said lever is cantedto the position shown in Fig. l, at which time platform 43 and housing44 are raised, this being the operative Weighing condition of thebalance. At such time it is desirable to prevent rotation of the housingwhich would cause the weights carried by segments 59 to turn with thehousing and thereby get out of alignment with the centering lug 35 ofthe weight support 34. A compression spring 12' may be provided as shownin Fig. 1 to maintain shaft 68 and associated elements in their properrelative positions.

It is to be understood that the balance described above and shown in thedrawing has been selected solely for the purpose of illustrating arepresentative example of my invention and that various changes may bemade in the details of construction and method of operation herein shownand described without departing from the scope and spirit of theinvention as defined in the appended claims.

The invention claimed is:

1. A balance comprising a standard, a beam having a knife edge pivotedon said standard, a movable cradle for lifting said beam on and off itspivot, a weight support pivotally suspended from said beam, a pluralityof weights adapted to be stacked one on top of the other on said 3support, a weight lifting device mounted on said balance having meansfor selectively lifting various numbers of said stacked weights on andoff said support, control means for operating said cradle, and meansoperated by said control means for preventing the operation of saidweight lifting device when said beam is on its pivot.

2. A balance comprising a pivoted beam, a weight support pivotallysuspended from said beam, a plurality of flat diamond-shaped weightsadapted to be stacked one upon the other in staggered relation on saidsupport so as to leave the outer ends of said weights free and clear ofeach other, and means for selectively engaging the free ends of saidweights and for lifting the engaged weight and those above it on and offsaid support.

3. A balance comprising a pivoted beam, a weight support pivotallysuspended from said beam having means for centering a plurality ofweights thereon, a plurality of fiat diamondshaped weights adapted to bestacked one upon the other in fan-like position on said support withtheir outer ends projecting clear of each other and having meansengageable with said centering means to hold them in such position onsaid support, and means for selectively engaging the projecting ends ofsaid weights and for lifting the engaged weight and those above it offand on said support.

4. A balance comprising a pivoted beam, a weight support pivotallysuspended from said beam having means for centering a plurality ofweights thereon, a plurality of fiat diamondshaped weights adapted to bestacked one upon the other in fan-like position on said support withtheir outer ends projecting clear of each other and having meansengageable with said centering means to hold them in such position onsaid support, rotating weight lifting members adjacent said supportadapted to be rotated selectively beneath the projecting ends of saidWeights, means for rotating said weight lifting members, and means forraising and lowering said weight lifting members to selectively liftsaid weights olf and on said support.

5. A balance comprising a standard, a beam having a knife edge pivotedon said standard, a movable cradle for lifting said beam on and off itspivot, a weight support pivotally suspended from said beam, a pluralityof fiat Weights adapted to be stacked one upon the other in fan-likeposition on said support with their ends projecting clear of each other,a rotatable and vertically movable weight lifting device adjacent saidsupport having means for selectively engaging said weights, a shaft forrotating said device for selecting said weights, means for raising andlowering said device to lift the selected weight off and on saidsupport, control means for operating said cradle, and means operated bysaid control means for locking said shaft to prevent rotation of saidweight selecting device when said beam is on its pivot.

JOHN GATTONI.

